Process of molding articles.



UNITED STATES PATENT OFFICE.

LEO H. BAEKELAND, OF YONKERS, NEW YORK, ASSIGNOR TO GENERAL BAKELITECOMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

Specification of Letters Patent.

No Drawing. Original application filed December 2, 1909, Serial No.531,000. Divided and this applicationfiled May 25, 1917.

To all whom it may concern Be it known that I, LEO H. BAEKELAND, acitizen of the United States, residing at Yonkers, in the county ofVestchester and State of New York, have invented certain new and usefulImprovements in Processes of Molding Articles, of which the following isa specification.

In my prior United States patents and applications I have describedseveral processes of forming objects consisting of the condensationproducts of phenols and formaldehyde, or containing such condensationproducts compounded with inert filling materials. For example, asdescribed in my U. S. Patents Nos. 942,699 and 942,700, patentedDecember 7, 1909, if a mixture of phenol or its homologues andformaldehyde or its polymers be heated, alone or in presence ofcatalytic or condensing agents, the formaldehyde being present in aboutthe molecular proportion required for the reaction orin excess thereof,that is to say, approximately equal volumes of commercial phenol orcresylic acid and commercial formaldehyde, these bodies react upon eachother and yield .a product consisting of two liquids which will separateor stratify on standing. The lighter or supernatant liquid is an aqueousso ution, which contains the water resulting from the reaction or addedwith the reagents, whereas the heavier liquid is oily or viscous incharacter and contains the first products of, chemical condensation ordehydration. The liquids are readily separated, and the aqueous solutionmay be rejected or the water may be eliminated by evaporation. The oilyliquid obtained as above described is found to be soluble in or misciblewith alcohol, acetone, phenol and similar solventsor mixtures of thesame. This oily liquid may be further submitted to heat on a waterorsteam-bath so as to thicken it slightly and to drive 011 any water whichmight. still be mixed with it. If the reaction be permitted to proceedfurther the condensation product may acquire a more viscous character,becoming gelatinous, or semi-plastic in consistence, and may even becomesolid and brittle when cold,

. again melting when gently heated. This modification of the product isinsoluble or incompletely soluble in alcohol but soluble Serial No.170,991.

or partially soluble in acetone or in a mixture of acetone and alcohol.All such condensation products are hereinafter referred to as partialcondensation products and may be subjected to further treatment ashereinafter described. By suflicient heating, any partial condensationproduct is transformed into a hard body, hereinafter referred to as thefinal product. This final product is unaffected 'by moisture, insolublein alcohol and acetone, infusible, and resistant to acids, alkalis andalmost. all ordinary reagents. It is suitable for many purposes, and maybe employed either alone or in admixture with other solid, semi-liquidor liquid materials, as for instance asbestos fiber, wood fiber, otherfibrous or cellular materials, rubber, casein, lampblack, mica, mineralpowders as zinc oxid, barium sulfate, etc., pigments, dyes,nitrocellulose, abrasive materials, lime,

Patented Mar. 19, 1918.

sulfate of calcium, graphite, cement, poworganic substances in the finalproduct may determine a softening action on the latter, which isespeclally pronoifnced at compar'atively high temperatures. Suchadditions impart new and valuable properties to these bodies, in thatthey arerendered plastic or capable of welding under pressure, yieldingthereby compact and coherent masses, bodies or articles, especially ifthe pressure be aided by heat. vSuch organic bodies as naphthalene,anthracene or other suitable fusible hydrocarbons having a relativelyhigh boiling-point, anilin, phenols, or other phenolic bodies, pitch,asphaltum, cumarin, resin, other resinous matters, paraflin, and ingeneral such substances as exert some solvent action, however slight,upon the initial or partial condensation products of phenols andformaldehyde and form therewith a solid solution, can be used for thispurpose. The fact as above mentioned that such organic bodies persist inthe final product and have a softening effect thereon is an indicationthat they form a so-called solid solution with this final product also.

- The substances as described above may be added to the initial reactingchemicals, or they may be introduced at any time during the reaction.They may furthermore be used in conjunction with suitable condensingagents or suitable filling materials.

By the addition of the above-described bodies which facilitate thewelding of the mass under pressure, it becomes possible to simplifyconsiderably the molding of articles from the final condensationproducts of phenols and formaldehyde. Indeed, these condensationproducts can be formed by the simple application of heat, Without theuse of special precautions for avoiding the production of spongy orirregular masses, and whatever the shape of the final mass may be it canbe easily introduced into suitable molds, preferably after beingcomminuted, and can then be pressed or consolidated into the desiredshape. The latter operation is greatly facilitated by the use oftemperatures exceeding 100 G., and preferably greatly exceeding thistemperature, whereby the softening effect is increased.

By the term phenols in the present specification and claims I intend todesignate not only ordinary phenol but its homologues or other phenolicbodies or mixtures thereof, which are equivalent to henol for thepurposes of this invention. nstead of formaldehyde, I may use thepolymers of formaldehyde, or in general such substances as are able to.engender formaldehyde in suitable condition.

henolic bodies,

conducted in such manner that during the a large amount of formaldehydeis or does not combine, thus produce heatin expelle ing a final productwhich contains an ex-.

cess of uncombined phenolic body capable of acting as a softening agent,and rendering the mass capable of welding as above described.

This application is a division of my copending application Serial No.531,000, filed December 2, 1909.

1. Process of making compact and coherent masses or articles containinga final infusible phenolic condensation product, which consists informing a final infusible condensation product compounded witha ma-.terial imparting .to the mass the capability of welding, andconsolidating fragments of the composition by causing surfaces thereofto unite or Weld under the influence of heat and pressure.

2. Process of making compact and coherent masses or articles containinga final infusible phenolic condensation product, which consists informing a final infusible condensation product compounded with amaterial imparting to the mass the capability of welding, subdividingthe mass, and consolidating fragments thereof under the influence ofheat and pressure.

In testimony whereof I affix my signature in presence of two witnesses.

LEO H. BAEKELAND.

